Abstract: Adding rubber powder instead of part of river sand into concrete can alleviate the black pollution of today 's waste tires. With C40 concrete as the matrix, rubber powder was used to replace the equal volume of river sand, and rubber concrete was prepared with 3%, 5% and 10% dosage. The rubber concrete was corroded in natural seawater and seawater rich in mixed bacteria for 30 days. The effect of microbial membrane on chloride ion permeability was studied by DC voltage accelerated permeability test (RCM) and electrochemical test. The results showed that compared with C40 concrete without rubber, the compressive strength of concrete with 5% rubber aggregate increased by 12% to 54.4 MPa, and the chloride ion diffusion coefficient decreased by 24.13%, which effectively improved the resistance of C40 concrete to chloride ion permeability in natural seawater. After microbial corrosion, the biofilm attached to the surface of the material was semi-transparent and cracked, and the polymorphic bacterial community was distributed on the membrane. This heterogeneous ruptured biofilm failed to play a protective role. The metabolic effect of bacteria greatly reduced the polarization resistance R_ct and impedance modulus |Z_w| of rubber concrete, and accelerated the diffusion process of chloride ions.